Get the raw buffer of ShaderEffectSource(qml2)

[stereoMatching]

Do anyone know how to obtain the raw buffer of ShaderEffectSource? I would like to do some postprocessing on it(save image, video record etc)

[wysota]

"Get" it where? You can use a shader effect to do postprocessing of the shader effect source. I don't think saving a single item is possible. You can grab the whole window, if you want.

[stereoMatching]

I can grab the whole window by grabWindow()
but it is too slow if I want to record the qml scene as video
That is why I want to get the raw buffer of the texture
rendered by shaderEffectSource and encode it into
a video file.

[wysota]

And you really think stopping the GL pipeline and transferring the image back to the CPU memory would not be slow?

[stereoMatching]

And you really think stopping the GL pipeline and transferring the image back to the CPU memory would not be slow?

You hit the point, looks like this is not a good solution.
What kind of solution could I use?

[wysota]

I think it depends how low-level can you go with your code. Tapping into QPA plugin would probably be best performance wide. But probably you can get away with using QQuickWindow::setRenderTarget() and passing an FBO that you can later convert to a image (possibly in another thread).